Own 2014 JGC. Had the emissions work done in June and experiencing lower mpg and turbo lag as most have. Regen a little more than before too. Also had to spend 771 bucks having the injectors cleaned because of check eng lt showing DTC fuel lower than expected. Been 6 weeks and appears to have solved the problem. Though injectors covered under ext. warranty this is not according to dealer. One of the parts of the service was adding a diesel lubricant 68194640-AB. Wondering if should add this myself every so often to prevent this from occurring again and if this is related to emissions update?